However, Trump has now confirmed that he intends to sue Maher for the full amount, filing papers in the state of California and accusing the comedian of going back on an "unconditional" offer, Politico reports.

"Bill Maher made an unconditional offer while on The Jay Leno Show and I, without hesitation, accepted his offer and provided him with the appropriate documentation," said Trump in a statement issued on Monday (February 4).

"Prior demands for payment went ignored by Mr Maher despite the fact that the beneficiaries of this suit will ultimately be the charities... who would share equally the $5 million - something I am certain they can desperately use."

Trump has announced that he would split the money between the American Cancer Society, Dana-Farber Cancer Institute, March of Dimes, Hurricane Sandy Victims and the Police Athletic League.

He later said on his Twitter page: "I don't know whether I will win or lose the @billmaher lawsuit but had an obligation to sue for charity."